A standard power brush had an arbor that extends along an axis and that is rotated at high speed about the axis. A brush has a sleeve fitted to the arbor and a multiplicity of bristles that extend radially outward from the arbor.
In use the brush is rotated at high speed while outer ends or tips of the bristles are pressed against a workpiece so as to strip paint, descale, deflash, roughen, or otherwise surface treat the workpiece. The bristles can be made of natural or synthetic fibers, or of metal.
With time the outer ends of the bristles often bulk up or become quite blunt, in particular when working hard materials such as metal castings or stripping paint. There is frequently a buildup on the rear sides of the bristles, that is the sides facing rearward in the peripheral rotation direction. This thickening and buildup reduces the effectiveness of the power brush by imparting a blunt shape to the bristles with an outer end providing little abrasive or scraping action. Once such a brush gets clogged in this manner, it is normally so difficult to clean it that it is simply discarded and replaced.